Osteotomy plate, plate driver and method for their use

Abstract

An orthopedic plate is specifically configured for use in osteotomies, in which part of the plate extends into a portion of a first bone segment and part is external to the cortical surface of an adjacent bone segment to fix the segments to allow them to fuse. The plate has a first end and a second end where the end which is inserted into the bone has a chamfer and a through hole having a hole axis optionally at an oblique angle to the longitudinal axis of the plate, and which can receive a screw, peg or pin. The second end of the plate includes a locking screw hole and optionally including a compression slot extending in a direction toward a screw hole in the opposing end. Optionally, the non-locking hole has a shroud that forms an arc or portion of a cylinder over the hole. A plate driver having a recess that holds the plate is used to insert the plate into the bone.

What is claimed is: 
     
       1. A plate for bone fixation comprising:
 a first end providing a cutting edge; 
 a tapered end which tapers from a lateral edge of the plate with a distal edge having a larger thickness to allow for a proximal portion of the plate to be driven into a bone; 
 a bottom surface configured for contact with a bone; 
 a top surface spaced-apart from the bottom surface, wherein an open-ended passageway communicates between the top surface and the bottom surface, the open-ended passageway being defined in offset relation to at least one of the top surface and the bottom surface, with a portion of the top surface circumferentially adjacent a top open-end of the passageway that is configured to receive a head of a screw within an angle of rotation of up to 20°; and 
 a shroud extending outward from the top surface at an oblique angle and covering at least a portion of the top open-end, the shroud adapted to be interposed between a tissue and the head of the screw so as to prevent tissue irritation and provide compression to the bone. 
 
     
     
       2. The plate of  claim 1 , further comprising a compression slot passageway communicating between the top surface to the bottom surface. 
     
     
       3. The plate of  claim 1 , wherein an axis of the passageway forms an angle of between 25° and 35° with the top surface. 
     
     
       4. A plate for bone fixation comprising:
 a bottom surface configured for contact with a bone; 
 a top surface arranged in spaced-relation to the bottom surface, wherein a first open-ended passageway is defined between the top surface and the bottom surface having a passageway axis and being sized to permit a screw to be inserted therethrough with an angle between a screw axis and the passageway axis to allow for a rotation of the screw about the passageway axis, the passageway configured to enclose a head of the screw wherein the passageway axis forms an angle with respect to the bottom surface between 10° and 45°; and 
 an arcuate shroud projecting outwardly from the top surface at an oblique angle and covering at least a portion of an open-end of the passageway, the shroud adapted to be interposed between a tissue and the head of the screw. 
 
     
     
       5. The plate of  claim 4 , wherein the angle of the passageway axis with respect to the bottom surface is between 15° and 40°. 
     
     
       6. The plate of  claim 4 , the angle of the passageway axis with respect to the bottom surface is between 25° and 35°. 
     
     
       7. The plate of  claim 4 , further comprising a second open-ended passageway is defined through the plate that communicates between the top surface and the bottom surface. 
     
     
       8. The plate of  claim 4 , further comprising a tapered crescent-shaped cutting edge. 
     
     
       9. A plate system for use in associated bone comprising:
 a screw having distal threads and a head having a surface without external threads; 
 a plate having a bottom surface configured for contact with a bone and a top surface with an open-ended passageway communicating between the top surface and the bottom surface, the open-ended passageway being defined in offset relation to at least one of the top surface and the bottom surface, with a portion of the top surface circumferentially adjacent a top open-end that is configured to receive the head of the screw at an angle wherein the passageway is shaped so as to permit the screw to be inserted therethrough with an angle between a screw axis and a passageway axis of up to 20°; and 
 a shroud projecting outwardly from the top surface covering at least a portion of the top open-end, the shroud adapted to minimize interaction between a tissue and the head of the screw. 
 
     
     
       10. The plate of  claim 9 , wherein the plate has a distal edge of the plate provides a shoulder so as to allow for a proximal portion of the plate to be driven into a bone. 
     
     
       11. The plate of  claim 9 , wherein an axis of the passageway forms an angle of between 10° and 45° with the top surface. 
     
     
       12. The plate of  claim 9 , wherein an axis of the passageway forms an angle of between 25° and 35° with the top surface. 
     
     
       13. The plate of  claim 9 , wherein a straight taper cutting edge is formed at an first end. 
     
     
       14. A plate system comprising:
 a locking screw having distal threads and a head having external threads; 
 a non-locking screw having distal threads and a head having a rounded rear Shoulder surface; and 
 a plate having a top surface and a bottom surface that is configured to be in contact with the bone, the plate having a first tab and a second tab aligned along a longitudinal axis of the plate and joined by a middle section defining a first hole in communication with the bottom surface; wherein the first tab terminates in a cutting edge configured to cut bone upon application of a driving force to the plate; wherein the second tab includes a locking screw hole, wherein the first hole defines a screw hole axis that forms an angle with respect to the longitudinal axis of the plate, the first hole permitting variation of an axis of a screw when rotated about the axis of the first hole; and a shroud which is formed on and raised above the top surface of the plate in order to sufficiently support the screw when it is received in the first hole and to shroud the head of the non-locking screw so as to minimize the possibility of tissue irritation from the head of the non-locking screw. 
 
     
     
       15. The plate system as set forth in  claim 14 , wherein the screw axis of the non-locking screw within the first screw hole can be varied with respect to the screw hole axis by up to 15° of conical rotation. 
     
     
       16. The plate system as set forth in  claim 14 , wherein the shroud forms a portion of a cylinder. 
     
     
       17. The plate system as set forth in  claim 14 , wherein the system further includes a drill guide which interacts with the second hole to allow a pilot hole to be drilled in the associated bone at a desired angle. 
     
     
       18. The plate system as set forth in  claim 17 , further including a plate driver which includes a recess into which the plate is configured to be seated for insertion of the plate into the associated bone. 
     
     
       19. The plate system as set forth in  claim 18 , wherein the plate driver further includes a handle having a longitudinal axis that projects in a direction parallel to the longitudinal axis of the plate when the plate is seated in the recess. 
     
     
       20. The plate system as set forth in  claim 19 , wherein the plate driver further includes a plate holder portion which includes the recess and which is attached to the handle such that when the plate is seated in the recess, the longitudinal axis of the plate is offset by a distance from the longitudinal axis of the handle. 
     
     
       21. The plate system as set forth in  claim 14 , further including a drill and a drill guide, wherein the drill guide can be mounted from the plate driver to guide placement of the drill to drill an opening into the associated bone for the first hole of the plate.